Static Site Generation (SSG)

With SSG, the framework — Next.js, Astro, Gatsby, and similar tools all support it — runs once during the build process, fetching whatever data each page needs and writing out the finished HTML for every route. Those pre-built files can then be served directly from a CDN edge location with no server computation happening per visitor request, which typically makes SSG pages the fastest possible option to serve, since there's no rendering work left to do at request time.

The tradeoff is freshness: because pages are built ahead of time, content changes aren't reflected until the next build runs — fine for a marketing page or blog post that changes occasionally, much less fine for a page showing live inventory or a personalized account dashboard. Modern frameworks address this with incremental approaches (Next.js's Incremental Static Regeneration, for instance) that let specific pages be rebuilt on a schedule or on demand without rebuilding the entire site.

The practical decision usually comes down to how often content changes and who needs to see it change instantly: a company's services pages are strong SSG candidates; a logged-in user's order history is not.